Follow Important Instructions - Honeywell RTH8500D Owner's Manual

Step 2. Follow Important Instructions
1. Do not connect the wires to the new thermostat based on wire
color because damage can occur to the heating and/or cooling
system.
These Installation Instructions explain later how to use the
enclosed wire labels to correctly mark the wires connected to
your old thermostat.
OLD THERMOSTAT
Y
G
GREEN
RC
YELLOW
WHITE
W
RED
R
ORANGE
5
!
DO NOT WIRE
NEW THERMOSTAT
BASED ON
WIRE COLOR.
M22034
69-1725-1